U.S. patent number 6,589,207 [Application Number 09/468,741] was granted by the patent office on 2003-07-08 for rapid exchange catheter having a support mandrel.
This patent grant is currently assigned to Advanced Cardiovascular Systems, Inc.. Invention is credited to Fozan El-Nounou.
United States Patent |
6,589,207 |
El-Nounou |
July 8, 2003 |
Rapid exchange catheter having a support mandrel
Abstract
Rapid exchange catheters having improved pushability and
trackability due to a support mandrel disposed within the inflation
lumen. The mandrel is secured at the proximal end of the catheter
shaft while the free distal end extends beyond the proximal
guidewire port. In an alternative embodiment, the catheter shaft
further comprises a sleeve in the inflation lumen that secures a
distal section of the support mandrel. The distal end of the
mandrel extends beyond the sleeve.
Inventors: |
El-Nounou; Fozan (Sunnyvale,
CA) |
Assignee: |
Advanced Cardiovascular Systems,
Inc. (Santa Clara, CA)
|
Family
ID: |
23861045 |
Appl.
No.: |
09/468,741 |
Filed: |
December 21, 1999 |
Current U.S.
Class: |
604/103.04;
604/96.01 |
Current CPC
Class: |
A61M
25/104 (20130101); A61M 25/0054 (20130101); A61M
2025/0183 (20130101) |
Current International
Class: |
A61M
29/02 (20060101); A61M 25/00 (20060101); A61M
029/00 () |
Field of
Search: |
;604/103.04,96.01,524,102.01,102.02,102.03,523,525 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
0 829 269 |
|
Mar 1998 |
|
EP |
|
WO92/17236 |
|
Oct 1992 |
|
WO |
|
Primary Examiner: Casler; Brian L.
Assistant Examiner: Sirmons; Kevin C.
Attorney, Agent or Firm: Fulwider Patton Lee & Utecht,
LLP
Claims
What is claimed is:
1. An intraluminal balloon catheter, comprising: an elongated
catheter shaft having a proximal end, a distal end, a distal
guidewire port in the distal end, and a proximal guidewire port
spaced closer to the distal end than to the proximal end; an
inflation lumen extending within the elongated catheter shaft; an
inflatable balloon disposed on a distal catheter shaft section,
having an interior in fluid communication with the inflation lumen;
a guidewire receiving lumen extending through a portion of the
elongated catheter shaft between and in fluid communication with
the distal guidewire port and the proximal guidewire port; and a
support mandrel disposed within the inflation lumen, having a
distal end that is unattached and which extends distal of the
proximal guidewire port; wherein the guidewire lumen and the
inflation lumen are substantially parallel at the proximal
guidewire port and coaxial distal of the proximal guidewire
port.
2. The catheter of claim 1, wherein the support mandrel has a
secured proximal end.
3. The catheter of claim 1, wherein the distal end of the support
mandrel extends to a section of the catheter shaft where the
guidewire lumen and the inflation lumen are coaxial.
4. The catheter of claim 1, wherein the mandrel has at least a
first tapered section having a proximal end located proximal to the
proximal guidewire port.
5. The catheter of claim 4, wherein the first tapered section of
the mandrel has a distal end located distal to the proximal
guidewire port.
6. The catheter of claim 1, wherein the mandrel includes a second
tapered section proximal to the first tapered section.
7. The catheter of claim 1, further comprising a sleeve disposed
within the inflation lumen and configured to receive a distal
section of the support mandrel.
8. The catheter of claim 7, wherein the distal end of the support
mandrel extends distally beyond the sleeve.
9. The catheter of claim 1, further comprising a sleeve disposed
within the inflation lumen and configured to receive a distal
section of the support mandrel.
10. The catheter of claim 9, wherein the distal end of the support
mandrel extends distally beyond the distal end of the sleeve to a
section of the catheter shaft where the guidewire lumen and the
inflation lumen are coaxial.
11. The catheter of claim 10, wherein the sleeve distal end is
within a section of the catheter shaft where the guidewire lumen
and the inflation lumen are parallel.
12. The catheter of claim 9, wherein the sleeve is about 0.1 cm to
about 150 cm long.
13. The catheter of claim 9, wherein a portion of the mandrel
located proximal to the mandrel distal end is secured to the
sleeve.
14. The catheter of claim 13, wherein the sleeve is secured to a
wall of the catheter shaft defining the inflation lumen.
15. The catheter of claim 1, wherein the proximal guidewire port is
proximal to the inflatable balloon.
Description
BACKGROUND OF THE INVENTION
Catheters designed for intravascular procedures such as angioplasty
must have a number of characteristics. Such catheters must be able
to transmit force along the length of the catheter shaft to allow
it to be pushed through the patient's vasculature. However, the
catheter shaft must also retain sufficient flexibility to allow it
to track over a guidewire through the often tortuous vasculature.
Additionally, the catheter must be able to cross stenosed portions
of the vascular anatomy. Prior art designs have supplemented
polymer catheter shafts with a stiffening wire or mandrel.
There is a need for rapid exchange catheters having improved
pushability, trackability and crossability providing enhanced
performance characteristics. The present invention addresses this
and other needs.
SUMMARY OF THE INVENTION
The invention is directed to a balloon catheter, preferably a rapid
exchange type catheter, having a mandrel in an inflation lumen
extending within the catheter shaft. The intravascular balloon
catheters of this invention generally comprise an elongated
catheter shaft having proximal and distal ends, an inflation lumen
extending within the elongated catheter shaft to a location in the
distal shaft section of the elongated shaft, and an inflatable
balloon disposed on a distal portion of the distal shaft section
having an interior in fluid communication with the inflation lumen.
A distal port is in the distal end of the catheter shaft, and a
proximal port is in the distal shaft section proximal to the
inflatable balloon. A guidewire receiving lumen extends through a
portion of the catheter shaft, between and in fluid communication
with the distal and proximal ports.
A support mandrel is disposed within the inflation lumen and has a
proximal end and a free distal end. The proximal end of the mandrel
should be secured in a proximal section of the catheter shaft, and
the mandrel distal end should extend distally of the proximal
guidewire port, and is preferably free.
In one presently preferred embodiment, the guidewire lumen and the
inflation lumen are substantially parallel to one another at the
proximal guidewire port and become coaxial to one another distal of
the proximal guidewire port. The free distal end of the support
mandrel should extend in the inflation lumen to at least the area
where the guidewire and inflation lumens become coaxial.
In another presently preferred embodiment, the catheter shaft
further comprises a sleeve to secure a distal section of the
support mandrel to a wall defining the inflation lumen. In this
embodiment, the distal end of the mandrel preferably extends beyond
the distal end of the sleeve and the sleeve is preferably disposed
adjacent to the proximal guidewire port.
The catheter of the invention has improved pushability and
crossability while maintaining more than adequate trackability due
to the support mandrel in the inflation lumen with a free distal
end located distal to the proximal guidewire port. A catheter with
the support mandrel of the invention also has excellent resistance
to catheter shaft kinking. Further, the design of this invention
maximizes the cross sectional area of the inflation lumen along the
length of the catheter while accommodating the support mandrel, to
consequently improve inflation and deflation times. These and other
advantages will become more apparent from the following detailed
description and accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, partially in section, of a rapid
exchange balloon catheter having a support mandrel that embodies
features of the invention.
FIG. 2 is a transverse cross-section of the catheter shown in FIG.
1 taken at line 2--2, showing the support mandrel secured in the
proximal section of the catheter adjacent the adapter.
FIG. 3 is a transverse cross-section of the catheter shown in FIG.
1 taken at line 3--3, showing the support mandrel disposed in the
inflation lumen of the proximal section.
FIG. 4 is a transverse cross-section of the catheter shown in FIG.
1 taken at line 4--4, showing the support mandrel disposed in the
inflation lumen at the junction of the proximal section and the
intermediate section.
FIG. 5 is a transverse cross-section of the catheter shown in FIG.
1 taken at line 5--5, showing the support mandrel disposed in the
intermediate section.
FIG. 6 is a transverse cross-section of the catheter shown in FIG.
1 taken at line 6--6, showing the junction of the intermediate
section and the distal section with the support mandrel disposed in
the inflation lumen and the guidewire disposed in the guidewire
lumen.
FIG. 7 is a transverse cross-section of the catheter shown in FIG.
1 taken at line 7--7, showing the guidewire disposed in the
guidewire lumen of the distal section.
FIG. 8 is a longitudinal cross sectional view of an alternate
embodiment of the invention, having a sleeve to secure a distal
section of the support mandrel.
FIG. 9 is a transverse cross-section of the catheter shown in FIG.
8 taken at line 9--9, showing the support mandrel secured in the
sleeve.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-7 illustrate a rapid exchange type balloon catheter 10
embodying features of the invention. Catheter 10 generally
comprises an elongated catheter shaft 11 having a proximal shaft
section 12 and a distal shaft section 13, an inflation lumen 14
adapted to direct inflation fluid from the proximal end of the
catheter shaft to the interior of an inflatable balloon 15 on a
distal portion of the catheter shaft, and a guidewire lumen 16
extending through distal section 13 of catheter shaft 11. An
adapter 17 and strain relief 18 are attached to the proximal end of
catheter shaft 11, and adapter 17 is configured to direct inflation
fluid into inflation lumen 14. A distal guidewire port 19 at the
distal end of catheter shaft 11 and a proximal guidewire port 20
are both in fluid communication with the guidewire lumen 16.
Proximal guidewire port 20 in the distal shaft section 13 is
proximal to balloon 15 and is spaced a short distance from the
distal end of the catheter shaft and a substantially greater
distance from the proximal end of the catheter shaft, so that the
proximal port is closer to the catheter distal end than to the
proximal end. A support mandrel 22 is disposed in inflation lumen
14.
The proximal end 23 of support mandrel 22 is secured at the
proximal end of catheter shaft 11, as shown in FIG. 2. Preferably,
proximal end 23 of support mandrel 22 is embedded in polymeric
material 24, although any conventional method of securing it may be
used. The distal end 25 of support mandrel 22 is free, and extends
distally beyond proximal guidewire port 20, as illustrated in FIG.
1. In one embodiment, support mandrel 22 is tapered at least at its
distal end to provide a smooth transition in flexibility and to
maximize the effective cross sectional area of inflation lumen 14.
In the embodiment illustrated in FIG. 1, the mandrel has a first
tapered section 26 which tapers gradually in a distal direction
from a location on the mandrel proximal to the proximal guidewire
port 20. In the embodiment illustrated in FIG. 1, the mandrel also
has a second tapered section 27 proximal to the first tapered
section. The second tapered section 27 preferably is located in a
distal portion of the proximal shaft section 12. In FIG. 1,
vertical lines are provided on the mandrel to illustrate the
location of the tapered sections 26/27, and would not necessarily
be visible on the actual mandrel. The first tapered section 26 is
typically about 1 to 5 cm long, preferably about 2 to about 3 cm
long, and the second tapered section 27 is about 1 to about 12 cm
long, preferably about 6 to about 7 cm long. The length of the
mandrel from the proximal end of the second tapered section 27 to
the distal tip of the mandrel, is typically about 10% to about 30%,
preferably about 15% to about 20% of the total length of the
mandrel. In the embodiment illustrated in FIG. 1, an intermediate
section 28 of the mandrel is provided between the first and second
tapered sections 26/27, having a constant diameter. Intermediate
section 28 of mandrel 22 is about 5 to about 20 cm long, preferably
about 8 to about 10 cm long. Distal end section 29 of mandrel 22
has a constant diameter and is typically about 1 to about 10 cm
long, preferably about 1 to about 2 cm long. In one embodiment, the
proximal end of the wire may have a diameter of about 0.01 to about
0.02 inch, preferably about 0.019 inch and it may taper to a
diameter of about 0.003 to about 0.006 inch, preferably about 0.005
inch at the distal end. Other dimensions may be employed depending
upon the construction of the catheter and its desired use. Support
mandrel 22 may be formed from a metal wire or other suitable
flexible material. Currently preferred materials include stainless
steel, MP35N, or nickel-titanium alloys.
In the embodiment of the catheter 10 illustrated in FIG. 1, the
catheter shaft has an intermediate section 32 between the proximal
shaft section 12 and distal shaft section 13. Preferably, the
intermediate section 32 is softer and more flexible than the
proximal shaft section, to provide a gradual stiffness transition
between the proximal shaft section 12 and the distal shaft section
13, and improve catheter shaft flexibility, maneuverability, and
pushability. In one embodiment, the intermediate section 32 is
formed of a polymeric material which is softer, i.e., lower Shore
Durometer hardness, than the polymeric material forming the
proximal shaft section. In the embodiment illustrated in FIG. 1,
the first tapered section 26 of mandrel 22 has a proximal end in
the intermediate catheter shaft section 32, and a distal end
distally beyond the distal end of the intermediate section 32.
The proximal shaft section 12 comprises a proximal tubular member
33 which defines inflation lumen 14 as shown in FIG. 3.
Intermediate section 32 comprises an intermediate tubular member 34
which is secured to the distal end of proximal tubular member 33
and which defines a section of the inflation lumen 14 beyond the
proximal tubular member 33, as shown in FIG. 4. The distal shaft
section 13 comprises an inner tubular member 35 with a proximal
section 36 that overlaps a distal section 37 of the intermediate
tubular member 34, and an outer tubular member 38 which is disposed
around the overlapping sections of the intermediate and distal
tubular members to secure the two tubular members together. The
outer tubular member 38 distal section is disposed coaxially around
the inner tubular member 35. The inner tubular member 35 has a
proximal end defining the proximal guidewire port 20 and a distal
end defining the distal guidewire port 19. Preferably, the
overlapping sections of the intermediate tubular member 34, inner
tubular member 35, and outer tubular member 38 are formed from
polymeric materials and fused together as illustrated in FIG. 6,
wherein inflation lumen 14 may have a generally "D" or
semi-circular shape, or a crescent shape following the fusing
operation. As shown in FIG. 6, the overlapped and fused sections of
the intermediate, inner and outer tubular members form a dual lumen
portion 41 of catheter shaft 11 such that inflation lumen 14 and
guidewire lumen 16 are substantially parallel in the overlap area.
Distal to intermediate tubular member 34, inflation lumen 14
becomes annular and coaxial with guidewire lumen 16, as shown in
FIG. 7. In the embodiment illustrated in FIG. 1, the distal end of
support mandrel 22 extends beyond proximal guidewire port 20,
preferably by a distance of about 1 to about 10 cm, most preferably
by about 2.5 cm, and into the coaxial portion of inflation lumen
14. Inflatable balloon 15 is sealingly secured at its proximal end
to the distal end of outer tubular member 38 and at its distal end
to the distal end of inner tubular member 35.
An alternative embodiment of the invention is shown in FIGS. 8 and
9, wherein catheter 10 further comprises a sleeve 42 around a
distal section of the support mandrel 22. Preferably, sleeve 42 is
disposed within the inflation lumen and secured to intermediate
tubular member 34 to secure a distal section of support mandrel 22.
The distal end of support mandrel 28 extends beyond the distal end
of sleeve 42 by about 1 to about 10 cm. In the embodiment
illustrated in FIG. 9, the sleeve and mandrel therein is offset
from the center of the inflation lumen 14 in a side section of the
inflation lumen 14. However, in alternative embodiments, the sleeve
42 and mandrel 22 therein may be located in other sections of the
inflation lumen 14 (not shown). In the embodiment of FIG. 9, the
sleeve is secured to one side of the wall defining the inflation
lumen in the intermediate tubular member 34. In one embodiment,
sleeve 42 has an outer diameter of about 0.014 in and this provides
the inflation lumen 14 adjacent sleeve 42 with dimensions of about
0.007 in by 0.017 in. As shown in FIG. 9, the intermediate, inner,
and outer tubular members may be fused to secure them, forming dual
lumen portion 41 of catheter shaft 11, as discussed above.
The sections of catheter shaft 11 can be formed by conventional
techniques, as for example by extruding, from materials already
found useful in intravascular catheters such a polyethylene,
polyvinyl chloride, polyesters and composite materials. High
strength polyamides may also be suitable. In additional to fusing,
the various components may be joined by heat shrinking or use of an
adhesives, such as acrylonitrile based adhesives.
The dimensions of catheter 10 are determined largely by the size of
the guidewires to be employed and the size of the artery or other
body lumen through which the catheter must pass. Generally, the
diameter of the guidewire lumen 16 is sufficient to accommodate a
guidewire 44 and to allow it to be slidably disposed therein. The
diameters of guidewires for coronary use can vary from about 0.006
to about 0.035 inch (0.2-0.89 mm) in diameter, and the inner
diameter of the guidewire lumen 18 of the catheter 10 should be
about 0.001 to about 0.005 inch (0.025-0.127 mm) larger than the
diameter of the guidewire. In one embodiment, the proximal section
12 and coaxial section of the distal section 13 have an outer
diameter of about 0.034 in and the fused overlapped dual lumen
portion 41 has an outer diameter of about 0.042 in.
The catheter shaft 11 is sufficiently long to extend from outside
the proximal end of a guiding catheter, which likewise extends out
of the patient, to a stenosis to be treated within the patient's
vascular system (or other desired location therein), e.g. from
about 100 to about 150 cm when a Seldinger approach through the
femoral artery is employed to introduce the catheter 10 into the
patient's vasculature. The intermediate shaft section is typically
about 1 to about 30 cm long, and preferably about 5 to about 10 cm
long. Preferably, the proximal guidewire port 26 is at least about
3 cm and may be up to about 60 cm from the distal end of the
catheter shaft, and more preferably about 20 to about 50 cm. The
mandrel 22 is typically about 80 to about 140 cm, preferably about
110 to about 120 cm in length.
The catheter 10 of the invention can be inserted into the patient
in a conventional rapid exchange fashion with the guidewire 44
preloaded within the guidewire lumen 16 and extending proximally
through proximal guidewire port 20. Catheter 10 may be withdrawn
and a replacement catheter mounted onto the proximal end of
guidewire 44 by inserting the proximal end of the guidewire through
a distal guidewire port 19 in the distal end of the replacement
rapid exchange type catheter and advancing the catheter over the
guidewire disposed within a guidewire lumen 16 of the replacement
catheter until the guidewire exits proximal guidewire port 20. The
proximal end of the guidewire is held while the replacement
catheter is advanced within the patient in a conventional
manner.
While the present invention is described herein in terms of certain
preferred embodiments, those skilled in the art will recognize that
various modifications and improvements may be made to the invention
without departing from the scope thereof. Moreover, although
individual features of one embodiment of the invention may be
discussed herein or shown in the drawings of the one embodiment and
not in other embodiments, it should be apparent that individual
features of one embodiment may be combined with one or more
features of another embodiment or features from a plurality of
embodiments.
* * * * *